1 #region Copyright notice and license 2 3 // Copyright 2018 gRPC authors. 4 // 5 // Licensed under the Apache License, Version 2.0 (the "License"); 6 // you may not use this file except in compliance with the License. 7 // You may obtain a copy of the License at 8 // 9 // http://www.apache.org/licenses/LICENSE-2.0 10 // 11 // Unless required by applicable law or agreed to in writing, software 12 // distributed under the License is distributed on an "AS IS" BASIS, 13 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 14 // See the License for the specific language governing permissions and 15 // limitations under the License. 16 17 #endregion 18 19 using System; 20 21 namespace Grpc.Core.Interceptors 22 { 23 /// <summary> 24 /// Provides extension methods to make it easy to register interceptors on Channel objects. 25 /// </summary> 26 public static class ChannelExtensions 27 { 28 /// <summary> 29 /// Returns a <see cref="Grpc.Core.CallInvoker" /> instance that intercepts 30 /// the channel with the given interceptor. 31 /// </summary> 32 /// <param name="channel">The channel to intercept.</param> 33 /// <param name="interceptor">The interceptor to intercept the channel with.</param> 34 /// <remarks> 35 /// Multiple interceptors can be added on top of each other by calling 36 /// "channel.Intercept(a, b, c)". The order of invocation will be "a", "b", and then "c". 37 /// Interceptors can be later added to an existing intercepted channel, effectively 38 /// building a chain like "channel.Intercept(c).Intercept(b).Intercept(a)". Note that 39 /// in this case, the last interceptor added will be the first to take control. 40 /// </remarks> Intercept(this Channel channel, Interceptor interceptor)41 public static CallInvoker Intercept(this Channel channel, Interceptor interceptor) 42 { 43 return new DefaultCallInvoker(channel).Intercept(interceptor); 44 } 45 46 /// <summary> 47 /// Returns a <see cref="Grpc.Core.CallInvoker" /> instance that intercepts 48 /// the channel with the given interceptors. 49 /// </summary> 50 /// <param name="channel">The channel to intercept.</param> 51 /// <param name="interceptors"> 52 /// An array of interceptors to intercept the channel with. 53 /// Control is passed to the interceptors in the order specified. 54 /// </param> 55 /// <remarks> 56 /// Multiple interceptors can be added on top of each other by calling 57 /// "channel.Intercept(a, b, c)". The order of invocation will be "a", "b", and then "c". 58 /// Interceptors can be later added to an existing intercepted channel, effectively 59 /// building a chain like "channel.Intercept(c).Intercept(b).Intercept(a)". Note that 60 /// in this case, the last interceptor added will be the first to take control. 61 /// </remarks> Intercept(this Channel channel, params Interceptor[] interceptors)62 public static CallInvoker Intercept(this Channel channel, params Interceptor[] interceptors) 63 { 64 return new DefaultCallInvoker(channel).Intercept(interceptors); 65 } 66 67 /// <summary> 68 /// Returns a <see cref="Grpc.Core.CallInvoker" /> instance that intercepts 69 /// the invoker with the given interceptor. 70 /// </summary> 71 /// <param name="channel">The channel to intercept.</param> 72 /// <param name="interceptor"> 73 /// An interceptor delegate that takes the request metadata to be sent with an outgoing call 74 /// and returns a <see cref="Grpc.Core.Metadata" /> instance that will replace the existing 75 /// invocation metadata. 76 /// </param> 77 /// <remarks> 78 /// Multiple interceptors can be added on top of each other by 79 /// building a chain like "channel.Intercept(c).Intercept(b).Intercept(a)". Note that 80 /// in this case, the last interceptor added will be the first to take control. 81 /// </remarks> Intercept(this Channel channel, Func<Metadata, Metadata> interceptor)82 public static CallInvoker Intercept(this Channel channel, Func<Metadata, Metadata> interceptor) 83 { 84 return new DefaultCallInvoker(channel).Intercept(interceptor); 85 } 86 } 87 } 88